FORT MCMURRAY, Alta. - Federal NDP Leader Tom Mulcair toured Alberta's sprawling oilsands Thursday, saying he was left agog at the size of the operations, but also with a renewed determination to make sure it all gets cleaned up.

"These are extraordinary undertakings on a human scale. I mean they're massive," Mulcair said at the Alberta legislature in Edmonton after his trip.

"We were able during the helicopter part to really take in a vast vista of what was being accomplished.

"It's extraordinarily impressive. But it also brings with it real challenges that if we don't assume in this generation we're going to bear in future generations."

He positioned himself as one with Alberta and Alison Redford on the need to develop the oilsands in a responsible way.

"I think your premier and I might be on the same page when I hear the idea of a greener energy infrastructure for the future," he said.

But he has not been on the same page, perhaps not even the same book, as Redford and other western provinces in recent weeks.

The two sides have swapped public insults and condemnations after Mulcair stated that the booming resource sector, particularly the oilsands, are driving up the Canadian dollar and thereby hurting the manufacturing sectors of central Canada — an economic phenomenon known as "Dutch disease."

Mulcair said that debate, and an invitation, prompted him to move up by a few weeks a planned trip to Suncor's operation near Fort McMurray, which he took Thursday along with Alberta NDP MP Linda Duncan, federal NDP environment critic Megan Leslie and NDP energy critic Peter Julian.

He avoided the term Dutch disease Thursday, but reiterated that companies are making high profits because they don't have to pay to clean up the land, air and water that they pollute. That inflates the dollar and hurts exporters in the rest of the country.

He cited a study released Wednesday by the Alberta-based Pembina Institute. It concluded that Canada is suffering from "oilsands fever" — the benefits of which are unevenly shared across the country and could lead to economic turmoil down the road.

But he emphasized that his fight is not with the premiers, but with Harper.

"The federal government is failing to enforce existing legislation and right now that's starting to cause serious problems in the ecosystems in question," he said.

Mulcair's stance is much less inflammatory than the diatribes that his predecessor, Jack Layton, used to inflict on the "tar sands."

After flying over the oilsands region during the 2008 election, Layton blasted Harper for refusing to "protect the North from the toxic discharges of his friends in the big oil companies."

Redford was in the United States at a conference Thursday, so Mulcair met with Alberta deputy premier Thomas Lukaszuk in Edmonton.

Lukaszuk said he made it clear that Alberta makes no apologies for how it does business and has no plans to turn the other cheek when criticized.

"I have highlighted to Mr. Mulcair that as Albertans we are proud of our record (and) that we do what we can to extract our resources in an environmentally responsible manner," Lukaszuk said.

"And (I told him) that any attacks against this province relevant to our economic impact on the rest of the country or our environmental impact on the rest of the country will not be accepted and are not welcome."

Mulcair's visit may have been a big deal on the political scene, but it appeared to be just another day in Fort McMurray.

After the Suncor tour, Mulcair met with the region's mayor, Melissa Blake. No one stopped him or tried to talk to him as he walked to City Hall for his meeting with Blake. There was no one waving signs or jeering.

Fort McMurray is used to visitors wanting to see the oilsands firsthand — everyone from high-powered politicians to Hollywood film directors such as James Cameron.

The region has become a international symbol of Alberta's economic might but also a reference point for a raging global debate on the price of progress.

The scale of the operations is mammoth. Massive machines, seeking out the prized bitumen, scrape the earth raw for kilometres in all directions, dumping the soil into massive dump trucks with wheels that dwarf nearby pickup trucks.

The refining process leaves behind great inland lakes of toxic sludge. Air cannons can be heard firing off at regular intervals to keep birds from landing on the ponds, getting caught in the goo and dying.

Blake said she doesn't entirely disagree with Mulcair's concerns about environmental sustainability.

"His passion is deep for the advances he's trying to make in environmental legislation," she said. "He's got some valid points. He's got some that I disagree with. But overall I respect ... the visit he made to our region and the time that he spent while he was here."

And she gave Mulcair credit for meeting with locally elected officials.

"I value and respect everyone who takes the time to come to the region to get the lay of the land."